Oil-resistant flexible rubber joint nitrile material performance comparison
Oil-resistant flexible rubber joint nitrile material performance comparison
Nitrile rubber itself is a product with many varieties, complicated uses and relatively small dosage, unlike the large market capacity of bulk rubber such as SBR, but NBR is also an indispensable rubber type in the field of rubber products. At present, domestic devices have the disadvantages of small scale, high raw material consumption and energy consumption, and high cost. From the perspective of product quality, imported NBR is better than domestic products in terms of quality, variety and after-sales service. While domestic NBR has the advantage of real estate price.
NBR is produced from butadiene and acrylonitrile through emulsion polymerization. NBR is mainly produced by low-temperature emulsion polymerization method. It has high oil resistance, high wear resistance, good heat resistance and strong adhesion. Its disadvantages are poor low temperature resistance, poor ozone resistance, poor insulation performance, and slightly lower elasticity. NBR is mainly used for manufacturing oil-resistant rubber products. NBR for short is a synthetic rubber made of butadiene and acrylonitrile copolymer. It is a kind of synthetic rubber with good oil resistance (especially alkane oil) and aging resistance. There are five kinds of acrylonitrile content (%) in NBR: 42-46, 36-41, 31-35, 25-30, 18-24. the more acrylonitrile content, the better the oil resistance, but the cold resistance will drop accordingly. It can be used in air at 120℃ or oil at 150℃ for a long time.
Generally speaking, increasing the crosslink density can improve the oil resistance of vulcanized rubber. In oxidized fuel oil, NBR vulcanized with peroxide or semi-vulcanized system has better oil resistance than NBR vulcanized with sulfur. Peroxide vulcanized NBR is stable at 40°C, but less stable at 125°C. Vulcanized cadmium-sulfur system NBR joints have good long-term heat resistance aging performance in oxidized fuel oil at 125°C.
The use of nitrile rubber flexible joints is the production of oil-resistant hoses and flame retardant conveyor belts, accounting for about 50% of the total usage; followed by sealing products, accounting for about 50% of automotive sealing products; also used in wire and cable, adhesives, printing and luggage products. In addition, NBR and other materials have also become a hot spot for research on blending modification. Using dynamic vulcanization technology, NBR/PVC, NBR/PP, NBR/EPDM, NBR/PS, NBR/CSM, NBR/polyamide, NBR/butyl rubber and other blends can be prepared. NBR/PCV blends are widely used in wire and cable industry. With the rapid development of communication industry, EPDM/PP has strong competitiveness in the field of submarine cable. At present, there are nearly 10,000 wire and cable enterprises in China, consuming a large amount of NBR/PCV every year. In addition, the mixture is also used in the outer layer of oil and fuel lines, automotive waterproof seals and moldings, foam insulation materials and rubber rings.
